Beverly Crusher
Commander Beverly Crusher, M.D. (born Beverly Cheryl Howard), played by actress Gates McFadden, is a fictional character on the television series Star Trek: The Next Generation and its subsequent spinoff films. She was a regular character in the show for all but the second of its seven seasons.
Crusher is the chief medical officer on board the USS Enterprise-D and its successor, the USS Enterprise-E. Crusher holds the rank of Commander, and was the head of Starfleet Medical during 2365. She has one son, Wesley, with her late husband, Jack Crusher.
Crusher is often depicted as intelligent, compassionate, caring, and strong willed; she is occasionally portrayed as defiant, occasionally siding with characters who seem to play the role of underdog and often plays devil's advocate in the senior staff meetings. Critic Robin Roberts opines that this character "is shaped more by her femininity than by her medical, scientific training."
During the second season, actress Gates McFadden was replaced by Diana Muldaur, who played Chief Medical Officer Dr. Katherine Pulaski. On the show, Crusher's absence was attributed to her being promoted to head of Starfleet Medical. McFadden returned to the role of Crusher in season 3, allegedly due to a lack of chemistry between Muldaur and the rest of the cast.
Read more about Beverly Crusher: Casting, Character Information